964 turbo not cranking

[JKK]

Hi, i´m working on a 1992 964 3.3 turbo . the car needs a major service, so i remove the engine, perform the work, but after reinstall, i found a "no cranking " condition.

checked the starter and it´s asossiated wiring, and found everything o.k, indeed if i bridge the yellow cable from the main harness connection (flat one on the driver side engine bay) the starter cranks o.k, so my engine harness , main 12v , and grounds are o.k
But i´m not getting any 12v signal from the ignition switch.
i have acces to 964 carrera 2/4 wiring schematics, but found a totally diferent thing on the car.
I´m looking for advice and information about the starter circuit, does it uses a starter relay? (looks possible since i found no closed circuits between the yellow cable at the engine bay and any of the ignition switch terminals)
if so... where is that relay located?
is possible to obtain the starter circuit schematics for this car? i´m an piwis user, but can´t find any info there!

thanks in advance for your help and inputs!

Juan

[JKK]

new notices... i just made some "reverse engineering " and found that the yellow starter cable makes it´s way up to the pin 9 of the "multifunction relay" 965.618.130.00 bellow the driver seat, if i bridge 12v to the 9th pin in the harness the starter cranks.
found the relay very rusty, inside, but can´t figure how this relay can drive the starter
so, still wanting any info about the starter wiring , or the relay function (pin out)
any one?

[jrhb]

The part number you referenced is the Turbo Control Unit (TCU) and a pin 9 failure there is a common failure point on 964 Turbos. See post 13 onwards in this thread: 1991-965-no-power-wur

Post 21 in that thread has a good description of what should be hooked up to the TCU. I don't think the starter should be routed through there, perhaps some custom wiring?

[JKK]

you´re right! check it again and the starter signal is present al pin number 4, and should be(according to a tuttorial at club911.net france), but still no signal from starter switch... i´m gettin close, but need starter switch pin out... i remove the switch, and found that every pin shows 12v at position 1 , nothing changes at position 2....
is the starter switch diferent in a 965 vs 964c2?
thanks for the link!
Juan